Calcium aluminosilicate

The two-layered laser flash method has been applied to some molten systems above 1000 K. In Fig. 30 an example of curve fitting is shown for molten calcium aluminosilicate at 1723 K. An analysis in which the radiative component is taken into account gives a good fit. The thermal conductivity and the radiative component parameter can be determined simultaneously by a curve-fitting procedure. 

On mixing the cement paste, the calcium aluminosilicate glass is attacked by hydrogen ions from the poly(alkenoic acid) and decomposes with liberation of metal ions (aluminium and calcium), fluoride (if present) and silicic acid (which later condenses to form a silica gel). 

Schmidt, W., Purrmann, R., Jochum, P. Glasser, O. (1981a). Calcium aluminosilicate glass powder and its use. European Patent Application 23,013. 

The glasses used by Steenbock in his original compositions were mixtures of calcium aluminosilicates and beryllium silicates but, as Dreschfeld reported in 1907, subsequent developments moved away from the use of beryllium compounds. Published chemical analyses in the period to 1916 (Voelker, 1916a Greve, 1913 Watts, 1915) confirmed Dreschfeld s statement. In the following we shall refer to these as oxide glasses. 

Molecular sieves (zeolites) are artificially prepared aluminosilicates of alXali metals. The most common types for gas chromatography are molecular sieve 5A, a calcium aluminosilicate with an effective pore diameter of 0.5 nm, and molecular sieve 13X, a sodium aluminosilicate with an effective pore diameter of 1 nm. The molecular sieves have a tunnel-liXe pore structure with the pore size being dependent on the geometrical structure of the zeolite and the size of the cation. The pores are essentially microporous as the cross-sectional diameter of the channels is of similar dimensions to those of small molecules. This also contrilsutes to the enormous surface area of these materials. Two features primarily govern retention on molecular sieves. The size of the analyte idiich determines whether it can enter the porous... 

Anortal [Anorthosite aluminium] A process for extracting alumina from anorthosite ore (a calcium aluminosilicate) by leaching with hydrochloric acid, precipitating aluminum trichloride hexahydrate, and calcining this. Developed and piloted by I/S Anortal in Norway in the late 1970s but not commercialized. 

In addition to the aforementioned interactions with the surrounding gas environments, metallic interconnects also interact with adjacent components at their interfaces, potentially causing degradation of metallic interconnects and affecting the stability of the interfaces. One typical example is the rigid glass-ceramic seals, in particular those made from barium-calcium-aluminosilicate (BCAS) base glasses [205-209], FSS interconnect candidates have been shown to react extensively with... 

The formation of barium chromate often leads to the physical separation of the sealing glass and the metal alloy due to barium chromate s high thermal expansion. Along interfacial regions where oxygen or air access is blocked, chromium or chromia can react with barium-calcium-aluminosilicate (BCAS) glass-ceramic to form a chromium-rich solid solution and a series of pores. 

Z.G. Yang, K.S. Weil, K.D. Meinhardt, J.W. Stevenson, D.M. Paxton, G.-G. Xia, and D.-S. Kim, Chemical compatibility of barium-calcium-aluminosilicate base sealing glasses with heat resistant alloys, in Joining of Advanced and Speciality Materials... 

Z. Yang et al., Chemical Compatibility of Barium-Calcium-Aluminosilicate-Based Sealing Glasses with the Ferritic Stainless Steel Interconnect in SOFCs, Journal of the Electrochemical Society, 150(8), pp. A1095-A1101 (2003). 

Calorimetric data on sodium and calcium aluminosilicate crystals and glasses (Navrotsky et al., 1982, 1985) indicate that, in an exchange reaction of type... 

Molecular sieves are used in a variety of fuel processing applications. Uses include drying and water removal from fuel, product purification, hydrocarbon separation and catalysis. Molecular sieves are composed of sodium and calcium aluminosilicate crystals which have been produced from natural or synthetic zeolite compounds. The crystals are dehydrated through heating and are processed to ensure that pore sizes are tightly controlled. 

MacDowell, J. F. 1991. Stratlingite and hydrogamet from calcium aluminosilicate glass cements. In Special Cement Advanced Properties, Mater. Res. Soc. Symp. Proc., 179, 159-179. 

CASH CBM CBO CBPC CC CCB CCM CCP CDB CEC CFBC CFC CFR CMM COP CSH CT Calcium aluminosilicate hydrate Coal bed methane Carbon burn-out Chemically-bonded phosphate ceramics Carbonate carbon Coal combustion byproducts Constant capacitance model Coal combustion product Citrate-dithionate-bicarbonate Cation exchange capacity Circulating fluidized bed combustion Chlorofluorocarbon Cumulative fraction Coal mine methane Coefficient of performance Calcium silicate hydrate Collision theory... 

Figure 12.9(a) is a picture of a silicon carbide fibre (Nicalon) in a calcium-aluminosilicate glass matrix. This picture is taken from a detailed study of... 

Fig. 12.9. A silicon carbide fibre in a calcium-aluminosilicate glass matrix (a) ELSAM, 1.9 GHz, z= —3.2 pm (b) calculated contrast from eqns (12.2), (12.45), and (12.46), horizontal scale the same as (a), with tick spacing 2.5 pm this time the experimental parameters gave the best fit without any adjustment (Lawrence 1990).

Calcium Aluminosilicates. Two in number, have been prepared by high-temperature methods and identified 2CaO AhOi SiCL. gehlinile CaO- AI Oi 2SiO . anorthite. 

A broader definition than that confined to solutions is demanded in some fields of chemistry (e.g., in high temperature reactions of acids, bases, and salts). In the foimation of metallulgical slags, at furnace tempeiatuies, calcium oxide is used as base and silicon oxide and aluminum oxide as acids calcium aluminosilicate is produced as a fused salt. Sodium carbonate and silicon oxide when fused react to form the salt sodium silicate with the evolution of carbon dioxide. In this sense ... 

Multiple matrix cracking perpendicular to the fibre axis was also reported by Blissett et al. (1997) for a UD Nicalon /CAS (calcium aluminosilicate) (Fig. 15.6). The density of these cracks increased with increasing AT but showed a reduction for AT> 800°C, which seemed to be consistent with the formation of strong silica bridging between the matrix and the fibres. 

Multiple matrix cracking perpendicular to the fibre axis due to thermal shock in UD Nicalon /CAS (reprinted from Journal of Materials Science 32(2) 1997, Thermal shock behaviour of unidirectional silicon carbide reinforced calcium aluminosilicate Blissett, Smith and Yeomans, Figure 2, with kind permission of Springer Science and Business Media). 

Blissett, M.J., Smith, P. A., Yeomans, J.A. (1997), Thermal shock behaviour of unidirectional silicon carbide fibre reinforced calcium aluminosilicate , J. Mater. Sci., 32, 317-325. Blissett, M.J., Smith, P.A., Yeomans, J.A. (1998), Flexural mechanical properties of thermally treated unidirectional and cross-ply Nicalon-reinforced calcium aluminosilicate composites , J. Mater. Sci., 33, 4181 —4190. 

Molecular sieve, 5A 225 Air and light gas analysis H2, 02, N2, (CH4, CO, NO, SFe co-elute) Synthetic calcium aluminosilicate (zeolite), having an effective pore diameter of 0.5 nm, C02 is adsorbed strongly 5A usually gives the best results of all synthetic zeolites should be activated before use and used above critical adsorption temperature 21.6% (mass/mass) water capacity... 

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